秸秆覆盖与保水剂对土壤结构、蒸发及入渗过程的作用机制

通过保水剂、秸秆覆盖、灌水等措施的实施,对冬小麦收获后各相应处理土壤样品的土壤结构特征、蒸发及入渗过程机制进行研究。结果表明：不同保水措施增加了土壤有机质含量,降低了土壤密度,提高了土壤结构的稳定性,降低了土壤团聚体的分形维数,减少了土壤水分无效蒸发,提高了土壤入渗能力;土壤入渗过程曲线拟合方程符合函数y=a＋be-cx,稳定入渗速率变化基本和a值的变化一致,c值决定了入渗速率降低的速度;经过小麦生命周期后,与灌水处理相比,施用保水剂后不进行灌水,土壤结构稳定性相对提高,土壤累计入渗量增加,土壤无效蒸发降低;玉米收获后未翻耕的样地提高了土壤有机质含量、土壤水稳性团聚体含量和土壤入渗性能。

Effect mechanism of straw mulching and water retaining agent on soil structure, evaporation, and infiltration process

Based on the application of water-retaining agent,straw mulching,and irrigation,investigating soil structure characteristics,the mechanism of evaporation and infiltration process are studied.The results show that: different measures of water-retaining increase the content of soil organic matter,reduce soil bulk density,improve the stability of soil structure,reduce fractal dimension of soil aggregates,decrease soil evaporation,and improve the infiltration capacity.Regression equation of soil infiltration rate follows y=a+be^-cx. The change of infiltration rate follows the change of value a;The decrease rate of infiltration is determined by the value c.Through the lifecycle of Triticum aestivum L.,compared with the treatments of irrigation,the application of water-retaining agent in the treatments of no-irrigation increase soil structure stability,infiltration amount,reduce soil evaporation.On harvested maize plots under non-tillage the content of soil organic matter was increased significantly,the soil moisture-stable aggregates and soil infiltration properties were improved,and evaporation was reduced compared with CK.